NASA/TM—2013–216595

An Overview of NASA's Subsonic Research 

Aircraft Testbed (SCRAT)

Ethan Baumann, Joe Hernandez, and John C. Ruhf

Dryden Flight Research Center, Edwards, California

 

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October 2013
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NASA/TM—2013–216595

An Overview of NASA's Subsonic Research 

Aircraft Testbed (SCRAT)

Ethan Baumann, Joe Hernandez, and John C. Ruhf

Dryden Flight Research Center, Edwards, California

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National Aeronautics and

Space Administration

Dryden Flight Research Center

Edwards, CA 93523-0273

October 2013
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NASA Center for AeroSpace Information

7115 Standard Drive

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443-757-5802
1

Abstract

National Aeronautics and Space Administration Dryden Flight Research Center acquired a 

Gulfstream III (GIII) aircraft to serve as a testbed for aeronautics flight research experiments. 

The aircraft is referred to as SCRAT, which stands for SubsoniC Research Aircraft Testbed. The 

aircraft’s mission is to perform aeronautics research; more specifically raising the Technology 

Readiness Level (TRL) of advanced technologies through flight demonstrations and gathering

high-quality research data suitable for verifying the technologies, and validating design and 

analysis tools. The SCRAT has the ability to conduct a range of flight research experiments

throughout a transport class aircraft’s flight envelope. Experiments ranging from flight-testing of 

a new aircraft system or sensor to those requiring structural and aerodynamic modifications to 

the aircraft can be accomplished. The aircraft has been modified to include an instrumentation 

system and sensors necessary to conduct flight research experiments along with a telemetry 

capability. An instrumentation power distribution system was installed to accommodate the 

instrumentation system and future experiments. An engineering simulation of the SCRAT has 

been developed to aid in integrating research experiments. A series of baseline aircraft 

characterization flights has been flown that gathered flight data to aid in developing and 

integrating future research experiments. This paper describes the SCRAT’s research systems 

and capabilities. 

Nomenclature

AC alternating current

ACTE Adaptive Compliant Trailing Edge

AFRL Air Force Research Laboratory

AFSRB Airworthiness and Flight Safety Review Board

ARR ACTE risk reduction

CDR Critical Design Review

CFD Computational Fluid Dynamics

COTS commercial off-the-shelf

CPT control position transducer

DC direct current

DFRC Dryden Flight Research Center

DRE Discrete Roughness Element

DRELFGE DRE Laminar Flow Glove Experiment

EGI embedded GPS INS

ERA Environmentally Responsible Aviation

FAA Federal Aviation Administration

FOSS fiber optic sensing system

FRR Flight Readiness Review

FTE Flight Test Engineer

G gravity

GIII Gulfstream III

GPS global positioning system

IADS Interactive Display System

INS inertial navigation system

INU inertial navigation unit

IR infrared

IRIG-B inter range instrumentation group mod B

KCAS knots calibrated airspeed
2

M Mach number

MCR Mission Concept Review

Mmo maximum operating Mach

MOA Memorandum of Agreement

MOU Memorandum of Understanding

NASA National Aeronautics and Space Administration

NRC National Research Council

NTP network time protocol

ORD Objectives and Requirements Document

PC personal computer

PCM pulse code modulation

PDR Preliminary Design Review

PDS power distribution system

PID Parameter Identification

RF radio frequency

SCRAT SubsoniC Research Aircraft Testbed

SRR Systems Requirement Review

TAMU Texas A&M University

TM telemetry

TRL Technology Readiness Level

Vmca minimum controllable airspeed

Vmo maximum operating velocity

Vstall stall speed

WATR Western Aeronautical Test Range

Introduction

The National Research Council’s (NRC)’s report on “Recapturing NASA’s Aeronautics Flight 

Research Capabilities” (ref. 1) made several recommendations regarding the development of 

flight research experiments and testbed aircraft. The report recommends, “NASA should ensure 

that each of its projects has a defined path to in-flight testing in an appropriate environment.” 

Another recommendation is to “... develop flight research vehicles to demonstrate innovative 

aerospace technology in flight.” In line with these recommendations, the National Aeronautics 

and Space Administration (NASA) Dryden Flight Research Center (DFRC) (Edwards, California) 

acquired a Gulfstream III (GIII) aircraft (Gulfstream Aerospace Corporation, Savannah, 

Georgia), tail number 804, to serve as a testbed for aeronautics flight research experiments.

The aircraft is commonly referred to as SCRAT, which stands for SubsoniC Research Aircraft 

Testbed (fig. 1). The aircraft is used to perform aeronautics research, and more specifically to 

raise the Technology Readiness Level (TRL) of advanced technologies, through flight 

demonstration, and gathering high-quality research data suitable for verifying the technologies 

and validating design and analysis tools. Historically, experimental aerodynamic and fluid 

mechanics investigations were primarily conducted in ground-based wind-tunnel facilities. 

However, these wind-tunnel facilities often imposed certain limitations such as scaling effects 

related to using sub-scale wind-tunnel models and an inability to match Reynolds number, noise 

levels, and boundary conditions (ref. 2). In some instances, conducting an investigation in flight 

using the flying wind-tunnel concept, where an aircraft is used as a carrier vehicle for an 

experiment, avoids some or all the wind-tunnel limitations. 
3

ED12-0191-26 

Figure 1. SCRAT in flight. 

The SCRAT was identified in the NRC’s report as an example of the type of flight research 

testbed that NASA should be developing. This paper provides an overview of SCRAT’s 

research capabilities along with additional ground based tools that support the aircraft. In 

addition, two SCRAT flight research projects are discussed to provide examples of the aircraft’s 

capabilities as a research platform. 

SCRAT Overview 

The SCRAT has been developed as a flight research platform for the purpose of raising the 

TRL of advanced, environmentally responsible technologies suitable for transport class aircraft. 

To serve this purpose, the SCRAT has been outfitted with a research quality instrumentation 

system. The SCRAT power system has been modified to support a power distribution system 

designed to accommodate the instrumentation and research systems. In addition, the cabin 

interior includes workstations for researchers and instrumentation engineers to monitor research 

experiments and aircraft systems. A telemetry capability has been added to the SCRAT, which 

allows for control room monitoring of critical parameters during envelope expansion flights, and 

allows for additional ground based researchers to monitor the status of their experiments. 

A series of flight tests, known as the baseline aircraft characterization flights, has been 

conducted to gather flight data suitable for characterizing the aircraft’s aerodynamics and for 

gathering data required to support follow-on experiments. Data from these flights have been 

used in documenting the aircraft’s baseline stability and control characteristics prior to planned 

modifications. The baseline flights also characterized the airdata system to ensure that research 

quality aircraft state and performance data can be obtained. 

An engineering simulation has been developed which models the SCRAT’s flight 

characteristics. The simulation contains aircraft models tailored to simulate the SCRAT systems 
4

and performance. The aircraft models have been updated based on flight data obtained during 

the baseline flights, therefore the simulation provides an accurate representation of SCRAT’s 

in-flight handling qualities, flight dynamics, and flight performance. In addition, a fixed based 

simulation capability has been created which allows the pilots to examine the aircraft’s flight 

characteristics with research experiments added. Engineers and pilots use this simulation to 

conduct airworthiness analysis to clear the aircraft for flight with the research experiments. 

The SCRAT research systems, aircraft modifications, baseline flight data, and engineering 

simulation provide a powerful capability for flight-testing of advanced aeronautics research 

experiments. In addition, the experience gained from modifying and operating the SCRAT is 

contained in an experienced, multi-disciplinary team at NASA DFRC that is ready to support 

flight research experiments. 

Vehicle Description

The SCRAT is a GIII, which is a twin-turbofan swept-wing business jet built by Gulfstream 

Aerospace Corporation. The SCRAT is powered by two Rolls Royce Spey RB turbofan engines 

(163-25) 511-8 (Rolls Royce Group PLC, London, England), which are capable of providing a 

maximum continuous power of 10,940 lb at sea level. Thrust reversers are fitted to each engine 

to reduce landing distance. Figure 2 contains a 3-view of the SCRAT. Table 1 details the 

SCRAT dimensions along with the allowable weights, airspeeds, altitudes, and G-limits. The 

service ceiling of the SCRAT is 45,000 ft and the maximum velocity is 340 knots calibrated air 

speed (KCAS) and a maximum Mach number of 0.85. The full SCRAT flight envelope, which 

does vary by the gross weight of the aircraft, is provided in figure 3. The SCRAT has an empty 

weight of approximately 38,000 lb and a maximum takeoff weight of 69,700 lb. Maneuvering 

limitations placed on the SCRAT consist of -1 g to 2.5 g with the fowler flaps retracted and 

decrease to 0 g to 2 g with the fowler flaps extended.

Figure 2. 3-view of the SCRAT.
5

Figure 3. SCRAT flight envelope.

Table 1. SCRAT dimensions and operating limits.

Dimensions

Length 83 ft 2 in

Wingspan 77 ft 10 in

Height 24 ft 4.5 in

Wing area 934.6 ft2

Mean aerodynamic chord 12 ft 3 in

Aspect ratio 6:1

Wing sweep 36 degrees

Weights

Empty weight 38,000 lb

Max takeoff weight 69,700 lb

Max landing weight 58,500 lb

Altitude Max operating altitude 45,000 ft

Airspeeds

Vmo (max operating velocity) 392 mph/340 knots Below 28,000 ft

Mmo (max operating mach) 0.85 Above 28,000 ft

Vmca (minimum controllable 

airspeed)

115 mph/100 knots

M (max range cruise) 0.75-0.76

Performance

Max range 3400 nm

Endurance Up to 7 hours, 

typically <=5 hours

G-limits G limits – fowler flaps retracted -1 g to 2.5 g

G limits – fowler flaps extended 0 g to 2.0 g

The SCRAT has been modified to support research experiments within the nominal SCRAT

transport-class-aircraft flight envelope, and operations throughout the entire SCRAT nominal 

flight envelope were demonstrated during the baseline flights. Future large-scale flight 
6

experiments integrated onto SCRAT might result in flight envelope restrictions depending on the 

nature of the experiment and the structural, aerodynamic, and control limitations of the SCRAT.

Either the pilot or copilot can fly the SCRAT through the use of their control yoke and rudder 

pedals. These pilot inceptors are directly connected to each control surface through a series of 

cables and pulleys. In addition, tandem type hydraulic actuators are used to operate each 

control surface in order to reduce control forces. Longitudinal control is provided by the elevator 

control surface, with longitudinal trim control provided by the elevator trim surface. The SCRAT

stabilizer is coupled with the aircraft fowler flaps to longitudinally re-trim the aircraft as the flaps 

deploy and retract. The ailerons and spoilers are mechanically linked to provide lateral control. 

Lateral trim is achieved through the use of the aileron trim. The rudder provides directional 

control, with the rudder trim providing the directional trim capability. Fowler flaps are used for 

takeoff and landing. In addition, the spoilers deploy after touchdown to decrease landing 

distance. The pilots are aided by an autopilot system and yaw damper.

The maximum cruise range for the SCRAT is 3,400 nm. The SCRAT is capable of flying up

to 7 hours assuming cruise conditions. To date, SCRAT flights have ranged from approximately 

2 hours to approximately 5.5 hours.

SCRAT unique limitations are rules prohibiting flight through visible moisture and avoidance 

of all precipitation while on the ground. These limitations are required to protect the unique

research systems and sensors located external to the aircraft cabin.

SCRAT Concepts of Operation

The SCRAT has been developed with the capability to support a large range of flight 

experiments relevant to multiple disciplines. The experiments can range from sensor 

development, to testing of new aircraft and research sensors and systems, to aircraft 

aerodynamic modifications, to advanced cockpit displays, and to airspace management.

SCRAT lacks a research flight control capability, but does have the potential to support controls 

experiments related to autopilot development or testing of new control actuators. The range of 

experiments that can be accommodated is largely limited by the imagination of the researcher.

The possible experiments generally fall into two categories: large and small-scale flight 

research experiments. Large-scale flight research experiments are defined as those 

experiments, which require significant structural, aerodynamic, system, instrumentation, or 

control changes to the aircraft. Examples of large-scale flight research experiments are 

modifications to the wing shape and replacing existing control surfaces with novel structures. 

Small-scale flight research experiments are defined as those experiments, which do not require 

significant structural, aerodynamic, system, instrumentation, or control changes to the aircraft. 

Examples of small-scale experiments are flight-testing of a new external sensor, new GPS 

receiver, or another system requiring little more than power and data connections.

Experiment Development, Integration, and Flight Process

The lifecycle for experiments flown on SCRAT go through four distinct phases: experiment 

proposal phase, design phase, buildup and integration phase, and a flight phase. Figure 4

shows an overview of the experiment development, integration, and flight process along with a 

summary of the activities during each phase and the typical design reviews. Early on in the 

development of a flight experiment, the DFRC project team, DFRC chief engineer, and the 

experimenter will jointly tailor the process to meet the specific needs of each flight experiment 
7

flown on SCRAT. The process shown in figure 4 is representative of that for large-scale 

experiments, and certain elements may be shortened or combined for small-scale experiments.

Figure 4. Overview of the experiment development, integration, and flight process.

Experiment Proposal Phase

The Experiment Proposal phase lays the foundation for potential collaboration through 

research, test, and evaluation between NASA DFRC and potential experimenters. The intent 

during this phase of the mission planning is to define the scope, objectives, requirements, 

schedule, cost, and hazards associated with a mission or experiment. A conceptual design is

generated during this time to aid in requirements development. The generation of a
8

Memorandum of Agreement (MOA) or Memorandum of Understanding (MOU) between NASA 

DFRC and the customer occurs during this phase. A Mission Concept Review (MCR) may take 

place during the experiment proposal phase in order to provide an independent review of the 

conceptual design and the plans for the project.

All SCRAT experiments require an Objectives and Requirements Document (ORD) 

generated by the experimenter with the assistance of the SCRAT project team. This document 

is the key to defining specific objectives and requirements of the flight experiment. Information 

contained in the ORD includes the experiment objectives, scope, approach, requirements,

hardware/software requirements, qualifications, and ground test requirements. 

The experiment proposal phase culminates in a Systems Requirement Review (SRR). At the 

SRR, the experiment scope, objectives, and requirements are examined in detail to ensure they 

are well defined, well understood, and achievable. The conceptual design, preliminary hazards,

budget, and schedule are also discussed at the SRR.

Experiment Design Phase

Once the SRR has been successfully completed, and the ORD has been agreed to by all 

parties, the experiment enters the design phase. During this phase, the hardware and software 

aspects of the experiment are designed, airworthiness analysis begins, and a detailed approach 

is developed for integrating the experiment onto SCRAT. Airworthiness analysis is conducted to 

assess any experiment specific unique changes, which affect the SCRAT’s flight characteristics. 

Airworthiness analysis can include work by the SCRAT aerodynamics, flight controls, flight 

systems, and flight structures disciplines. Also during this time, the requirements and schedule 

are continuously tracked, and project and technical risks, and hazards are addressed. The 

design of experiment systems and equipment installations for use on SCRAT will follow 

standard aircraft industry design practice and Gulfstream design criteria. Current Federal 

Aviation Administration (FAA) standards are to be met to the maximum extent practical, 

consistent with the mission objectives. 

A preliminary flight-test plan is developed during this time frame. The flight-test plan will 

detail the flight conditions, flight maneuvers, and unique flight requirements for each experiment. 

The flight-test plan is useful in determining the number of flights and flight hours required for 

each experiment.

Typically, a Preliminary Design Review (PDR) is held at a mid-point in the design phase to 

provide an independent assessment of the state of the design and to solicit input from the 

stakeholders. The design phase culminates in a Critical Design Review (CDR) where the nearly 

finalized experiment design and related analysis is presented. Ideally, any experiment drawing 

packages are approximately 90 percent complete and very little, if any, flight hardware has been 

built or procured prior to CDR. Independent review teams are present at both the PDR and CDR 

in order to provide an outside perspective and expert opinion on the experiment design and 

progress.

Buildup and Integration Phase

Once the CDR has been completed, the procurement and build-up of the flight hardware 

begins, and the flight software is developed. The experiment hardware and software is tested 

extensively during this timeframe with some testing occurring prior to aircraft integration, and 

more testing occurring once integrated with the aircraft systems. 
9

DFRC is responsible for the integration of all experiments onto the SCRAT and will work 

closely with experimenters to ensure the proper integration. During this phase, requirements are 

tracked and verified either through test, analysis, or inspection to ensure that all experiment 

development requirements have been met. The airworthiness analysis unique to each 

experiment concludes during this phase. The flight-test plan is finalized during this phase. The 

buildup and integration phase is complete once the project is ready to proceed to the flight 

phase and begin the DFRC airworthiness and flight safety review process.

Flight Phase

The NASA DFRC flight approval process usually includes the completion of a Flight 

Readiness Review (FRR), an Airworthiness and Flight Safety Review Board (AFSRB), and 

technical briefings. The DFRC Chief Engineer may grant deviations from the basic flight 

approval process. For example, smaller or less complex experiments with minimal risk are often 

granted FRR and AFSRB waivers after review and approval by the DFRC Chief Engineer.

Larger flight experiments with more inherent complexity and risk will most likely require more 

reviews within the flight approval process. An experiment can be flown on SCRAT only after 

receiving approval from the DFRC Chief Engineer. The airworthiness review process often 

continues throughout the experiment flights with additional briefings occurring as needed.

Once approval has been given by the DFRC Chief Engineer to proceed, the project may 

begin experiment flights. Prior to any flight, the SCRAT instrumentation system, and the 

experiment are configured for flight in what are known as pre-flight procedures. The pre-flight 

procedures typically occur one or two days prior to a flight. A crew brief occurs the day prior to a 

flight. At the crew brief, all personnel involved in the flight gather to discuss the flight plan. The 

SCRAT flights typically occur in the military range around Edwards Air Force Base, but may

leave that range if required. Following a flight, a crew de-brief is held to discuss the flight events 

and develop plans for the next flight. The SCRAT, instrumentation system, and experiment are 

de-configured from flight status in a post-flight procedure that usually occurs the day after a 

flight. Flight data is available to the experimenter approximately 24 hours after the post-flight 

procedures are completed.

Large Scale Flight Research Experiments

Large-scale flight research experiments will typically require a few years to develop from 

conceptualization to integration and flight on SCRAT and will follow a lengthier airworthiness 

review process. The DFRC SCRAT project team will work with the developers of large-scale 

flight research experiments from the beginning in order to ensure the experiment can be

integrated and flown on the aircraft. These large-scale experiments will typically require a

significant multi-disciplinary engineering effort in terms of model development, analysis, and 

ground testing along with a series of envelope expansion flights to expand the flight envelope.

Envelope expansion flights are required for any experiment in which the SCRAT’s outer mold 

line has been changed or for which significant structural modifications have been made. During 

these envelope expansion flights, the aircraft will be minimally crewed and data will be 

telemetered to the ground for control room monitoring. Once the aircraft has been cleared for 

flight in certain portions of the flight envelope, control room support becomes optional and is 

dependent upon research and airworthiness requirements. At this point, the control room 

staffing would depend on the need to support the research goals or provide additional 

monitoring of the safety of flight parameters. In the cases where a control room is not required, 

cost and time savings can be achieved by recording all data onboard with researchers present 

in the cabin to monitor the progress of their research experiments.
10

Small Scale Flight Research Experiments

The development and integration times of small-scale flight research experiments will vary 

depending on the complexity of the experiment and integration activities, but it could be as short 

as a few months. An abbreviated airworthiness review process might be applicable in some 

cases depending again on the complexity of the flight research experiment. The DFRC SCRAT 

project team will work with the developers of small-scale flight research experiments from the 

beginning in order to ensure the experiment can be integrated and flown on the aircraft. These 

small-scale experiments would likely not require envelope expansion flights, thus incurring 

significant cost and schedule savings compared to the large-scale experiments. Small-scale 

flight research experiments would be monitored in flight by the researcher or a designee sitting 

at a workstation on the aircraft. If desired, the control room could support these small-scale 

research flights, but is not generally required.

Aircraft Capabilities and Research System Description

At the heart of the SCRAT’s research capabilities is the instrumentation system. The 

instrumentation system interfaces with the aircraft data bus and systems along with a number of 

research and airworthiness sensors. This section describes the instrumentation system 

capabilities and the available sensors.

Instrumentation System Description

The instrumentation system that has been integrated onto the SCRAT collects, processes, 

displays, telemeters, and records data obtained from multiple sources. The SCRAT contains an 

ARINC-429 (A429) avionics data bus that much of the aircraft systems interface with. The 

instrumentation system collects data from the aircraft A429 bus, as well as aircraft systems not 

on the A429 bus such as the engines and sensors located throughout the aircraft. The 

instrumentation system is currently configured to record approximately 1,200 parameters at data 

rates ranging from 1 Hz to 20,000 Hz. The instrumentation system has been designed to 

interface with future research systems and sensors.

Research Instrumentation Network

The instrumentation system provides an on-board local area network available to users and 

systems via Ethernet. All data acquired by the instrumentation system is available through this 

network. Research systems and researchers will have access to the network. The 

instrumentation system network is not connected to the Internet and has access restrictions in 

place to protect the network. IRIG-B (inter range instrumentation group mod B) and NTP 

(network time protocol) time, synchronized by a single GPS source, is distributed throughout the 

aircraft. These time sources allow for accurate, correlated time sources for all on-board data.

These time services are available through data panel connections located throughout the cabin.

Sensor Description

A number of sensors have been added to the SCRAT to acquire aircraft airworthiness and 

research data for a variety of flight projects. The list of sensors includes: wing pressure 

measurements, structural accelerometers, control surface positions, aircraft state information, 

airdata parameters, pilot inceptor inputs and forces, a hot film array, a fiber optic sensing 

system (FOSS), engine parameters, and wing strain measurements. Uses for the data obtained 

from these sensors include estimating the SCRAT’s rigid body aerodynamics, monitoring wing 
11

structural loads, assessing aircraft handling qualities and flight dynamics, measuring aircraft and 

engine performance, and characterizing the wing flow field.

Wing Pressure Distribution

Upper and lower wing pressure distributions are available at three span-wise locations on 

the left wing (fig. 5). At these locations, pressure ports have been installed in the wing leading 

edge and vinyl tubing, approximately 1 in wide and 0.1 in tall, and have been adhered to the top 

and bottom sides of the wing for the purpose of obtaining wing pressure distribution data. This 

data has been used to validate Computational Fluid Dynamics (CFD) models, and will be useful 

in supporting future research experiments. 

Figure 5. Location of wing pressure measurements.

Structural Accelerometers

Ten structural accelerometers have been placed on the aircraft to monitor aircraft structural 

modes. These accelerometers have been placed near the wing tips, the nose, and on the tail. 

The placement of the accelerometers allows for the measuring of the significant structural 

dynamics modes. Flight data from these accelerometers has been used to validate the 

structural dynamics model for the aircraft. Large-scale flight experiments will likely affect the 

aircraft’s structural dynamics, so these structural accelerometers provide an existing means of 

assessing those impacts in flight.

Control Surface Positions

The majority of the SCRAT control surface positions have been instrumented with a control 

position transducer (CPT). The CPTs are mounted to a control horn or bell crank as close as 

possible to the individual control surface to provide the most accurate knowledge possible of the 

surface’s position. Following is a list of the control surfaces instrumented: elevator, elevator 

trim, stabilizer, spoilers, ailerons, aileron trim, and rudder. The fowler flaps were not 

instrumented since they are set to discrete increments and are mechanically linked to the 

stabilizer, which is instrumented. Knowledge of control surface position is required for 

conducting Parameter Identification (PID) estimation of the aircraft rigid body aerodynamics. 
12

Airdata

The SCRAT is instrumented to acquire airdata information used to obtain knowledge of the 

aircraft flight condition. A combination of research quality sensors, aircraft instrumentation, and 

flight-based calibration curves are used to provide high-fidelity airdata measurements to support 

flight research. Table 2 lists the available airdata parameters.

Table 2. Available airdata parameters.

Airdata parameter Units

Indicated static pressure psf

Total pressure psf

Total temperature deg F

Impact pressure psf

Corrected impact pressure psf

Indicated Mach number

Freestream Mach number

Freestream static pressure psf

Freestream state 

temperature

deg F

Pressure altitude ft

Dynamic pressure psf

True velocity/ airspeed knots

Indicated airspeed knots

Equivalent airspeed knots

Calibrated airspeed knots

Freestream viscosity lb-sec/ft2

Freestream density lbm/ft3

Reynolds number 1/ft

In addition to the above listed airdata measurements, four flow angularity vanes have been 

fastened to the SCRAT’s radome to provide angle-of-attack and angle-of-sideslip 

measurements. Figure 6 shows the location of three of the flow angularity vanes on the SCRAT 

radome, with the 4th vane out of view. Flight data was used to develop calibrations for both 

parameters. The resulting calibrations for angle of attack are accurate to ± 0.26° and angle of 

sideslip is accurate to ± 0.55°.
13

ED12-0191-01

Figure 6. Flow angularity vanes (4th vane not visible).

Aircraft State Information

Aircraft state information is obtained through a combination of sensors. The SCRAT 

contains two aircraft inertial navigation units (INU)s that are used in conjunction with two 

research INUs installed on the aircraft to obtain three-axis aircraft attitude, rate, and 

acceleration data. The SCRAT production aircraft systems also provide aircraft velocity and 

position information. An embedded GPS INS (EGI) system is currently being integrated onto the 

aircraft in order to provide highly accurate aircraft angular rate, acceleration, velocity, and 

position information.

Control Inceptor Input Force and Position

The pilot’s yoke and rudder pedals are instrumented to measure pilot inceptor forces and 

position. The yoke longitudinal and lateral positions and input forces are measured along with 

the rudder position and input force. These data have been used to improve the fidelity of the 

ground-based piloted engineering simulation and is monitored in flight as an indication of pilot 

workload and aircraft state.

Hot Film Sensor Array

A 32-element Senflex hot-film sensor array (ref. 3) has been placed on the leading edge of 

the left wing. The hot-film array allows for non-intrusive measurements of the airflow. These 

measurements allow for identification of laminar to turbulent flow transition, stagnation points, 

shocks, boundary layer instabilities, and flow separation. A data acquisition system has been 

developed and integrated onto SCRAT to interface with the hot-film array. The hot film system is

capable of acquiring data at 20,000 Hz. The hot film array is currently being used to measure 

wing stagnation point and could be relocated as needed, or additional hot-film arrays could be 

placed on the aircraft. Figure 7 shows the hot film array located on the left wing leading edge.
14

 Photo Courtesy: NASA/John Ruhf

Figure 7. Hotfilm array placed on left wing leading edge.

Fiber Optic Sensing System 

A fiber optic sensing system (FOSS) (ref. 4) has been integrated on SCRAT. The FOSS 

uses light-weight fiber Bragg grating sensors to gather data that is processed to provide strain 

data which enables precise calculations of shape, stress, stiffness (bending and torsion),

temperature, pressure, strength, and operational loads in real time. Unlike conventional strain 

gauges, which are heavy, bulky, and spaced at distant intervals, the fiber optic sensors are 

relatively small, non-intrusive, and easy to install along with providing high-resolution (~0.5-in)

strain measurements. The system allows for numerous high-fidelity measurements of structural 

strain and displacement captured at rates fast enough to potentially examine dynamic structural 

response. The FOSS gives future researchers the capability to collect, record, and telemeter 

over 6,000 strain measurements.

Engine Parameters

The SCRAT is instrumented to provide engine data obtained from the two Rolls-Royce Spey

Mark 511-8 turbofan engines. The engine data is obtained directly from the production system 

and includes: fuel flow, engine pressure ratio, turbine gas temperature, high pressure 

tachometer, low pressure tachometer, engine oil temperature, and engine oil pressure. This 

data is currently being used to improve the SCRAT simulation drag and thrust models. In the 

future, this data can be used to provide a flight derived drag estimate for flight research 

experiments.

Wing Strain Measurements

Thirty-two strain gages have been attached to the left side wing surface at various locations, 

top and bottom to measure wing shear, bending, and torsion. The strain gages have been 

calibrated through the application of known loads to the airframe. Figure 8 shows the aircraft 

during a recent wing load calibration test. These strain gages allow for real-time monitoring of 

wing structural loads during flight-testing. For large-scale experiments, which require significant 
15

structural and/or aerodynamic changes to the aircraft, monitoring of the wing structural loads is 

an important risk mitigation step to ensure the structural loads are within the aircraft’s strength 

capability. This capability allows for safe, rapid test point clearance during envelope expansion 

flights. Figure 9 shows the location for each of the strain gages.

 Photo Courtesy: NASA Dryden Flight Loads Lab

Figure 8. Calibration of the wing strain gages.

Figure 9. Location of shear, bending, and torsion strain gages on the left wing.
16

Telemetry System Description

The telemetry (TM) system is capable of sending two instrumentation pulse code modulation 

(PCM) data streams and one video stream to the control room as required. PCM data stream 1 

contains the SCRAT data described in this paper. PCM data stream 2 is used for flight research 

experiments. These two separate PCM streams ease the integration of flight research 

experiments onto SCRAT since it is easier to generate a new PCM map specific to the 

experiment’s telemetry needs rather than to make modifications to the existing SCRAT data 

PCM map. A C-Band transponder allows the DFRC Western Aeronautical Test Range (WATR)

to track the aircraft during flight, which optimizes the radio frequency (RF) signal strength of all 

transmissions to the ground.

The C-Band Transponder, Data TM, and Video TM capabilities are listed below:

C-Band Transponder – Receive: 5660.0 MHz, Transmit: 5585.0 MHz, Decode: 

7 μseconds, Delay: 2.5 μseconds.

Data TM –Two SOQPSK transmitters are available for use. Lower-L, Upper-L, and 

S band are supported at data bit rates from 1-20 Mbps.

Video TM – Tunable C-Band transmitter, Frequency Range 4400.0 to 4999.0 MHz, 

programmable in 1 MHz steps. 

The instrumentation system is currently configured to telemeter 5.0 Mbps of data per stream 

for a total capability of 10.0 Mbps. The amount of data telemetered can be tailored for the 

specific needs of a flight research project.

Power Distribution System Description

The aircraft’s production electrical power distribution system (PDS) was not sufficient for the 

instrumentation power requirement. As a result, the production PDS was not used for the 

instrumentation system. An instrumentation PDS was designed and installed to provide power 

for the aircraft’s instrumentation and research systems. The instrumentation PDS is expected to 

accommodate the power requirements of future flight experiments.

On the ground, the instrumentation power system can receive power from the aircraft power 

system while powered by a ground power cart or hangar power, the aircraft APU, and/or the 

engines. During flight, the power system will receive power from the engines’ two alternators, 

which provide AC power, and two generators, which provide DC power. 

With the instrumentation system as currently configured, 120 A of 28 V DC and 90 A of 

115 V 60 Hz AC power is available for future flight research experiments. The instrumentation 

PDS also provides 115 V 400 Hz AC power to support sensor operation. 

Video System Description

The onboard video system has the capability to record up to eleven analog cameras, and 

telemeter one standard definition video channel for display in the control room. The telemetered 

video channel can either show the output of one camera or up to four in a quad arrangement. All 

cameras are accessible through web browsers on the aircraft network and can be accessed by 

any workstation on board in order to support flight research objectives.
17

Cockpit Modifications

A number of features have been added to the SCRAT cockpit to increase test point 

efficiency and to aid the pilots. A g-meter has been installed in the cockpit to allow the pilots to 

more accurately fly to a specified g-loading. Tablet PCs have been mounted to the pilot and 

co-pilot yokes. These tablets are integrated with the instrumentation system and can display 

data to the pilots during flight to aid in conducting a flight research experiment. For example, a 

desired airspeed or aircraft attitude could be provided to the pilot via the tablet PC in order to 

obtain a specified experiment test point. A master kill switch has been added to the center 

pedestal to enable the pilots to shut off power to all research systems in the case of an 

emergency. Figure 10 shows the location of the significant cockpit modifications.

Figure 10. SCRAT cockpit.

Cabin Description

The SCRAT cabin has been modified to accommodate the research systems and work 

stations. The SCRAT cabin can be reconfigured to support a wide array of flight research 

experiments. Located within the cabin are a number of racks, which contain the instrumentation,

power, and research systems. The current cabin layout is shown below in figure 11.
18

Figure 11. Current cabin layout.

Cabin Workstations

The cabin contains two permanent workstations. Each workstation has a display, keyboard 

input, and seat for a researcher or crew member. Personnel at each workstation can access all 

of the data through the SCRAT instrumentation system through a series of configurable 

displays. The first permanent workstation is located on the forward right side of the aircraft and 

is reserved for the Flight Test Engineer (FTE). The FTE assists the aircrew in the conduct of 

each research mission and monitors the experiment progress from the cabin. The FTE 

workstation display is shown in figure 12. The second permanent workstation in the cabin is 

referred to as the instrumentation station. The instrumentation station has been used to date by 

an instrumentation engineer who has monitored the instrumentation system health during flight. 

In the future, a researcher could use the instrumentation station. In addition to the two 

permanent workstations, space and provisions exist to place up to three additional workstations 

in the cabin to support future research needs. 
19

Photo Courtesy: NASA/John Ruhf

Figure 12. Station 1 FTE display.

Cabin Environment

Any electronic, electrical, and electromechanical equipment flown on SCRAT must conform 

to a certain level of environmental (temperature, pressure, and vibration) specifications. These 

specifications are generally met by testing the equipment on a mechanical shaker, which 

vibrates at specified frequencies and magnitudes, and through the use of an altitude chamber, 

which places the equipment at specified atmospheric pressures and temperatures. These 

environmental tests are used to detect any workmanship issues with the equipment early on 

and to ensure the equipment will operate in the expected flight environment. The end result of 

these environmental tests is an increase in the probability of a successful research flight. 

Table 3 details the environmental specifications for non-safety related equipment placed in the 

cabin.

Table 3. Non-safety critical cabin equipment environmental specifications.

Non-safety critical cabin equipment operation 

environment

Temperature 41o F to 110o F

Vibration Curve B1 from DO-160 category R

Pressure 0 to 10,000 ft

Communication System

The communications system that has been integrated to the aircraft is a commercial 

off-the-shelf (COTS) based system, which allows additional aircrew and researchers sitting in 

the cabin to communicate with each other and to the pilots. In addition, the communications 

system allows the FTE to use the co-pilot’s radio to communicate directly with the control room.
20

The communications system allows for close coordination between researchers and the pilots to 

ensure the required test points are achieved. 

Data and Power connections

Both AC and DC power connections are available at several locations in the cabin via wall 

outlets. Ethernet and serial connections are also available at these locations. The presence of 

these pre-existing power and data connections allows for flexibility in accommodating future 

flight research experiments. Figure 13 shows a representative set of power and data 

connections located in the cabin wall.

Photo Courtesy: NASA/John Ruhf

Figure 13. Representative data and power connections.

External Sensor Disconnect Panel

All of the sensors placed on the aircraft have wiring that runs from their location to the 

instrumentation system located in the cabin. The majority of the wiring associated with sensors 

placed outside of the cabin is routed to a location in the fuselage near the mid-point of the cabin 

where a pressure boundary pass-through exists. The sensor wiring comes into the cabin via this 

pass-through to a disconnect panel (fig. 14) located on the left side of the cabin above the floor. 

The disconnect panel allows physical access to this sensor wiring and is where the sensor 

signals are passed to the instrumentation system. The sensor disconnect panel and pressure 

boundary pass-through contain spare connectors to accommodate future research experiments.
21

Photo Courtesy: NASA/John Ruhf

Figure 14. Sensor disconnect panel.

Modified Exit Window

One of the SCRAT’s original emergency exit windows has been replaced with a custom 

emergency window containing two smaller panes of glass. One port is made of optical glass,

and the other is made of a Zinc-Selenide pane for infrared (IR) camera use. The exit window 

retains the function of the original emergency exit window (fig. 15). In addition a shelf, data 

connections, and power connections have been installed at this window location to allow for 

rapid integration of optical and IR cameras for viewing research experiments on the left wing.

Figure 16 shows the modified exit window, shelf, and a sample camera installation.

Figure 15. Modified emergency exit window.
22

Photo Courtesy: NASA/John Ruhf

Figure 16. Optical shelf.

Research Simulation

An engineering simulation was developed which models the SCRAT flight dynamics. The 

simulation utilizes the DFRC Core architecture (ref. 5) and contains aircraft models tailored to 

simulate the SCRAT systems and performance. The simulation can be run in either a real-time 

or batch mode of operation. The batch mode of operation allows the simulation to run as fast as 

the host computer can accommodate, which is significantly faster than real time allowing for 

numerous simulations to be rapidly run. The real-time mode of operation uses an external time 

source to execute the simulation in real time. The aircraft models have been updated based on 

flight data obtained during the baseline flights, therefore the simulation provides an accurate 

representation of SCRAT’s in-flight handling qualities, flight dynamics, and flight performance. 

Figure 17 shows a sample comparison between the simulation and flight data. The flight data is 

taken from the baseline flights during a large-amplitude rolling maneuver.
23

Figure 17. Sample comparison between simulation and flight data.

The effects of small- and large-scale flight experiments on the aircraft’s flight dynamics can 

be assessed with the engineering simulation. Engineers can conduct this assessment at their 

desk with the batch version of the simulation. This assessment includes airworthiness analysis 

such as an examination of available control power, performance, handling qualities, and flight 

characteristics. In addition, a fixed-base cockpit simulator (fig. 18) has been integrated with the 

engineering simulation to provide a basic piloted simulation capability. This piloted simulation 

allows for the research pilots to practice for missions and evaluate the SCRAT’s predicted flight 

dynamics prior to envelope expansion or research flights. This ability to predict and simulate 

SCRAT’s flight dynamics serves to prepare the pilots and greatly increases safety and mission 

success.

Photo Courtesy: NASA/Greg McCarthy

Figure 18. SCRAT fixed-base simulation.
24

Control Room Operations

The NASA DFRC WATR range engineering branch provides flight-test range development 

services and maintains two Mission Control Centers. The major services that the range 

engineering branch performs are range systems engineering, test information engineering, data 

processing, and display system/software development (ref. 6). The SCRAT project makes use 

of the range engineering branch services and can utilize either control room to monitor the

progress of research flights. Data available to the onboard instrumentation system can be

telemetered to the control room as well as recorded on board. The telemetered data can be

monitored in the control room in real time to assess the progress of flight research experiments 

and to ensure the flights are progressing safely. The control room displays for each discipline 

are created using the Interactive Display System (IADS). An example of an IADS display is 

shown in figure 19. The IADS display shown is used to monitor flight progress and aircraft 

status. A series of baseline displays for each discipline were developed for the baseline flights. 

Modifications to these displays to support future flight research experiments are relatively 

simple. In addition, the capability exists to execute algorithms provided by the project engineers 

or researchers in real time for display in the control room.

130217

Figure 19. Sample IADS display.

Control room operations were demonstrated during the baseline flights. Figure 20 is a view 

of the control room during a baseline flight. During these flights, the control room was used to 

improve test point efficiency, ensure flight safety, and to familiarize the SCRAT team with 

control room operations with this platform. Following each maneuver, engineers in the control 

room evaluated the maneuver and assessed whether a repeat was required. When a repeat 

was required, feedback was provided to the pilot concerning their technique and suggestions

made to improve the maneuver. Future research experiments will utilize a similar process to 

ensure the required data is collected.
25

 ED12-0220-43

Figure 20. Control room operations during Phase 0A flights.

One video stream was sent from the SCRAT during the baseline flights. This video stream 

was displayed in the control room and recorded.

Currently, data is available post-flight in the following formats: CMP (refs. 4 and 7) IADS 

archive (ref. 8), and Chapter 10 (ref. 9). In order to accommodate research needs, data can be 

made available in nearly any format desired. Flight data is typically available within 24 hours of 

the completion of a flight.

Baseline Flight Data

The baseline flights consisted of a series of flights, which gathered approximately 30 hours 

of data on the SCRAT’s flight characteristics to improve engineering and simulation models, and 

gather data to support the planned flight research experiments. Figure 21 shows the flight 

conditions that were flown during the baseline flights. During these characterization flights, data 

was gathered to calibrate several of the new research systems on the aircraft, including the

airdata system. In addition, the baseline flights verified and validated the SCRAT 

instrumentation system operation and instrumentation PDS modifications.
26

Figure 21. Baseline characterization flight data points.

During the baseline flights, the SCRAT was flown at select points throughout the flight 

envelope with the purpose of obtaining PID and handling quality data. This data was used to 

update the aerodynamics database and validate the updates. Control surface positions and pilot 

inputs recorded in flight were used to more closely match the handling qualities of the piloted

simulation to the aircraft. Wing pressure measurements recorded in flight characterized the flowfield over the left wing for future research projects. A limited set of engine performance data has 

been gathered to support future research experiments.

Flight Research Experiment Examples

Two flight research experiments have been developed to various extents for flight on 

SCRAT. The Discrete Roughness Element (DRE) Laminar Flow Glove Experiment (DRELFGE) 

was funded by NASA’s Environmentally Responsible Aviation (ERA) Project to modify a portion 

of the left wing to conduct flight research into using DREs as a laminar flow control method. The 

Adaptive Compliant Trailing Edge (ACTE) is funded by both ERA and the Air Force Research 

Laboratory (AFRL) (Wright-Patterson Air Force Base, Ohio) to flight-test large-scale compliant 

structures. The DRELFGE and ACTE projects are briefly discussed as examples of large-scale 

flight research experiments that can be flown on SCRAT.

DRE Laminar Flow Glove Experiment 

The DRELFGE was developed to demonstrate a passive laminar flow control technique at 

Reynolds numbers representative of a business class aircraft. The flow control technique to be 

explored is the DREs developed by Texas A&M University (TAMU) (College Station, Texas).

DREs are elements a few microns high and 1-2 millimeters in diameter that are placed near the 

leading edge to control cross-flow boundary layer instabilities. This technology has the potential 

to increase laminar flow over the wings thereby resulting in less drag and less fuel burn relative 

to current aircraft. The DRELFGE consisted of a highly instrumented wing glove (fig. 22) with a 
27

row of DREs installed, placed on the left wing of the SCRAT. The flight research conducted with 

the DRELFGE installed on the SCRAT would yield quantitative and qualitative data, which can 

be used to design a natural laminar flow airfoil. The qualitative data consists of an infrared 

image of the left wing, which would visually show the areas of laminar and turbulent flow. An 

infrared camera located inside the cabin would look through the modified exit window to obtain 

the infrared image of the wing. The quantitative data consists of wing pressure distributions,

temperatures, airdata, and aircraft state information. Various surface roughness configurations 

of the DRELFGE would also be tested to determine the utility of DREs in maintaining laminar 

flow on a surface painted similar to that of transport class aircraft.

Figure 22. Notional DRELFGE test section location.

The SCRAT’s wing chord, wing sweep, and flight envelope allow the exploration of 

technologies such as DREs at flight conditions representative of transport class aircraft. The 

SCRAT is an excellent platform for this type of work due to the existing instrumentation and 

power systems that can accommodate the additional research instrumentation. The SCRAT is 

also a good fit for accommodating experiments such as the DRELFGE since the wing structure 

can accommodate the additional structural loads associated with flying experiments such as 

this.

The DRELFGE wing glove design has been optimized for flight on the SCRAT (ref. 10),

passed a PDR in June of 2012, and is currently on hold while options to conduct this research 

are being evaluated.

Adaptive Compliant Trailing Edge 

NASA DFRC is working in conjunction with the AFRL and FlexSys, Inc. (Ann Arbor, 

Michigan) to design, develop, and fly the ACTE. The ACTE project will design, build, and flighttest two adaptive compliant composite flaps for integration on the SCRAT. Adaptive compliant 

control surfaces enable the development of adaptive airfoils. Numerous studies have shown the 

aerodynamic benefits of an adaptive airfoil, though a full-scale flight demonstration is needed to 
28

establish confidence in an adaptive compliant structure (refs. 11 and 12). The ACTE project is 

an interim step on the path towards developing and demonstrating compliant structures for 

aircraft design. The focus is on developing compliant structures and demonstrating their 

integration and flight; compliant structure actuation and demonstrating the aerodynamic benefits 

are not a part of the ACTE project. Figure 23 is an illustration of what the ACTE flaps will look 

like on SCRAT. The ACTE flaps will replace the SCRAT’s existing fowler flaps. The ACTE flaps 

will not be actuated in flight. Instead, each ACTE flap will be set to a pre-determined position on 

the ground prior to each flight. It is desired to fly the flaps at deflections ranging from -2o to +30o.

Figure 23. The ACTE installation on the SCRAT with inboard and outboard transition surfaces 

(blue) and a main flap (green).

The installation of the ACTE flaps requires the removal of the SCRAT spoilers along with 

numerous modifications to the aircraft systems. These spoilers provide approximately half of the 

pilot’s roll control performance, and their removal was identified as a risk. In order to mitigate 

this risk, a series of flights known as the ACTE risk reduction (ARR) flights was conducted. The 

ARR flights consisted of approximately 12 hours of flight time with the SCRAT’s spoilers 

disabled, thus replicating the roll control performance that the pilots can expect when flying the

ACTE flaps. In addition, several of the aircraft system modifications related to aircraft system 

alarms were implemented to verify them prior to flight testing the ACTE flaps. The ARR flights 

were very successful and demonstrated that the pilots can safely fly SCRAT with the flight 

spoilers disabled/removed. Prior to the ARR flights, the SCRAT simulation had been modified to 

replicate the predicted handling qualities of the SCRAT with the flight spoilers disabled. The 

pilots used the simulation to practice landing and maneuvering in advance of the flights, and 

they found this experience was instrumental to the success of the ARR flights.

Similarly to the DRELFGE experiment, ACTE is an example of how SCRAT’s capabilities 

enable the flight testing of novel experiments, such as new, large-scale control surfaces. For 

example, the SCRAT wing strain measurements are an important risk reduction feature for the 

ACTE project since they allow for real-time monitoring of the wing structural loads in flight,

thereby helping to ensure safe operation. In addition, ACTE demonstrates the depth and 
29

versatility of the SCRAT team in integrating an experiment which affects the aircraft’s 

aerodynamics, structural loads, flutter characteristics, and handling qualities.

The ACTE project completed a CDR in June of 2013. The ACTE flaps are undergoing initial 

build-up and plan to be integrated onto the SCRAT during 2013, with the flight-testing occurring 

in 2014. A control room will support the ACTE flights since this is a large-scale modification to 

the aircraft.

Conclusion

This paper described the SCRAT’s research systems and capabilities. The SCRAT can 

accommodate a range of small and large-scale flight research experiments. Coupled with the 

development of the ground-based tools and knowledge base, the SCRAT provides a powerful 

capability for NASA and the nation to perform aerodynamics research, raise the Technology 

Readiness Level (TRL) of advanced technologies, demonstrate technologies in flight, and 

gather high-quality research data suitable for verifying the technologies and validating design 

and analysis tools. 
30

References

1. National Research Council, Recapturing NASA’s Aeronautics Flight Research Capabilities,

The National Academies Press, Washington D. C., 2012.

2. Rae, William H. Jr., and Alan Pope, Low-Speed Wind Tunnel Testing, John Wiley and Sons, 

Inc., New York, 1984.

3. Tao Systems, Senflex® Multi-Element Surface Hot-Film Sensors, URL: http://www. 

taosystem.com/products/senflex/. Accessed September 11, 2013.

4. Bakalyar, John, “Fiber-Optic Strain Sensing (FOSS) Shape and Load Measurement 

Demonstration Tests,” National Aeronautics and Space Administration, Dryden Flight 

Research Center URL: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20110014495_ 

2011014995.pdf. Accessed September 11, 2013.

5. Curlett, Brian. P., “A Software Framework for Aircraft Simulation,” NASA/TM-2008-214639, 

2008.

6. National Aeronautics and Space Administration, Mission Information and Test Systems,

URL: http://www1.nasa.gov/centers/dryden/capabilities/CodeM/CodeMC/index.html.

Accessed September 11, 2013.

7. National Aeronautics and Space Administration, Flight Data Access System Programmer's 

Manual-2003, URL: https://dfrcshare.ndc.nasa.gov/Orgs/codeM/codeMI/Ops/DataCenter/ 

SitePages/FDAS%20Programmer%20Manual.aspx. Accessed September 11, 2013.

8. Symvionics, Incorporated, IADS Product Descriptions, URL: http://iads.symvionics.com/ 

productsdesc.html. Accessed September 11, 2013.

9. U.S. Army/WSMR, Telemetry Standards, RCC Document 106-07, Chapter 10, September 

2007 URL: http://www.wsmr.army.mil/RCCsite/Documents/106%20Previous%20Versions/

106-07/106-07%20Cover%20-%20TOC%20-%20Changes%20-%20Preface.pdf. Accessed 

September 11, 2013.

10. Hartshorn, Fletcher, Michael J. Belisle, and Helen L. Reed, “Computational Optimization of a 

Natural Laminar Flow Experimental Wing Glove,” AIAA-2012-870, 2012.

11. Sridhar, Kota, Russell Osborn, Gregory Ervin, Peter Flick, and Donald Paul, “Mission 

Adaptive Compliant Wing - Design, Fabrication and Flight Test,” Symposium on Morphing 

Vehicles, RTO-MP-AVT-168, Lisbon, Portugal, 2009, p. 18-1.

12. Nangia, Dr. Raj K., “Study for Air Vehicles at High Speeds Identifying the Potential Benefits 

to Transport Aircraft of a Continuously Variable Geometry Trailing-Edge Structure that can 

be Utilized for Aircraft Control, Trim, Load-Alleviation, and High Lift,” 

AFRL-AFOSR-UK-TR-2011-029, 2011.